John, working in the automotive industry I know that is petroleum. Which means any petroleum that is in the ardex that did not get encapsulated is floating. no big deal. It could simply be something they use so ardex doesn't stick to the container it is in or in the manufacturing process.

Vinyle acetate co polymer. Probably lighter than water so it floats. Take a dish and put in a tiny drop of motor oil in it. The sheen will be there. Take a tile spacer and drop it in a bucket. It floats. You have tested Ardex and you know it works well. Just be sure to clean the oil off before tiling.

FWIW, if I remember correctly, granite always contains at least these three minerals: mica, quartz, feldspar. Since sand can have many sources, it's not unreasonable that some of it could have been created from granite, but the majority of sand is quartz (highly purified suff might end up mostly quartz required for clear glass). But, mica does not disolve in water.

It's an interesting -- and timely-- review that you are doing. Too bad it's taken more than a year to complete it to your satisfaction

I am a layman homeowner who is just now putting in a 'custom' shower (36x58). My plan is to attempt a mud floor with a Kerdi drain, and cover it with Kerdi cloth (just enough material for the floor was given to me some time back) then up the sides about 8" with Kerdi-band. I'm not concerned with any warranty program so I'm thinking on using some Ardex X5 thinset under the Kerdi as well as for the field tiles -- that product was such a good choice for my other marble-tiled bath project. Have you used X5 under Kerdi?
The shower walls are just now Hardi'd. I then plan on using the Ardex 8+9 for the walls with overlap down onto the Kerdi clothed pan.

The Ardex package directions indicate that the Hardi seams and corners be filled and mesh-taped with the 8+9 -- no mention of pre-filling with thinset. But some of the gaps in the Hardi are large (about 1/4" at the niches for example). So what I propose to do is to first simply fill the Hardi with thinset and mesh-tape (as normal) then treat with the Ardex 8+9 as I did using the AquaDefense on my previous tub surround project. But my uncertainty here is with with the treatment of the corners as with the possibility of 2x4 stud movements. So, do you think the option of fully thinsetting the Hardi first would have any merit? As an aside, I've used Schluter eke for corner tile movement before and it seems to have worked as well as silicone.

Also, can the Kerdi be glued together successfully using the 8+9, or should I stick with the X5 or even Kerdi-fix? ..I'm not sure of your results as your review has yet to be finished.
And if so is there any advantage of just continuing the 8+9 over the whole Kerdi covered pan as a backup waterproofer? -- will it stick for the long term?

After resolving this, I also want to include building of a proper (low profile) curb. I figured I'd build it out of formed concrete. Is there a cationary method to use in doing this? I would also cover this with the Kerdi cloth ..and perhaps with a coat of 8+9 as well.